def fun01(n):
    i = 1
    t = 1
    while i<=n:
        t *= i
        i += 1
    return t

def fun02(c):
    x = 0
    y = 1
    while y<=c:
        x = x+fun01(y)
        y += 2
    return x

print('1!+3！+...19!=',fun02(19))